Oil soluble polymers



3,310,536 OIL SOLUBLE POLYMERS William A. Hewett, Oakland, Calif, assignor to Shell Oil Company, New York, N.Y., a corporation of Delaware No Drawing. Filed Dec. 10, 1962, Ser. No. 243,647 5 Claims. (Cl. 260-495) This invention relates to lubricants and particularly to highly detergent lubricants useful under severe operating conditions, such as under extreme high speed and at high temperatures, and to a new and novel class of polymeric additives therefor.

It is well known that the high pressure occurring in certain types of gears and bearings may cause rupture of lubricant films with consequent damage to the machinery. It is known that various base lubricants can be improved in their protective properties of rubbing surfaces by the addition of certain substances, so-called extreme pressure agents, so that excessive wear, scuffing and seizure are minimized or prevented.

It is known that certain compounds of metal-reactive elements, such as certain compounds of chlorine, sulfur and phosphorus, as well as certain other compounds, such as some compounds of lead, impart extreme pressure properties to various lubricants. Notable among the substances heretofore used are the lead soaps, phosphoric acid esters, free or bound'sulfur and certain chlorinated organic compounds. A principal objection to many of these extreme pressure agents is their lack of detergency and their high reactivity with the metallic surface, causing etching, corrosion and discoloration of the metal surface. Another objection to chemically reactive extreme pressure agents is that they alter the original chemical nature of the contacting surface, which under certain conditions is undesirable. Additionally, because of the activity of agents of this type, they usually are depleted rapidly resulting in only a temporary solution to the problem of extreme pressure lubrication.

It has now been discovered that improved detergent and extreme pressure lubricants are provided by a suitable lubricating oil containing oil-soluble high molecular weight non-ash halo-mercapto-containing polymeric compounds having essentially a long linear hydrocarbon backbone chain and attached thereto in a uniform or random fashion two kinds of essential groups, one an oil-solubilizing hydrocarbyl radical, preferably an alkyl radical having an average of between 8 and 20 carbon atoms (preferably 10-16) bonded directly to the hydrocarbon backbone chain or indirectly thereto through a polar group and the other an alkyl radical containing a halogen and an aryl mercapto group on adjacent carbons of the alkyl radical, which groups are at least two carbon atoms re moved from the main hydrocarbon polymer chain alkyl carbons. This polar substituted radical is represented by the formula Halo s-Q ice from zero to 2. The number of units (I) in the final polymer can vary from 10 to 1000 or more, preferably from 100 to 800, inclusive. Polymers of this invention contain a plurality of units represented by where x, y, 2, Q and X are as defined, m is a whole num! her, and Y is an oil-solubilizing radical containing a C C alkyl radical attached directly or indirectly to the main backbone chain through a polar group such as where Z is hydrogen or an alkyl radical. The molecular weight of the polymer varies from about a thousand to about a million, preferably from 10,000 to 500,000.

The oil-soluble halo-mercapto aryl containing polymers of the above type are prepared by reacting aryl sulfenyl halides with an oil-soluble unsaturated linear hydrocarbon polymer which, in turn, is prepared by polymerizing a polyene hydrocarbon with a monoolefinically polymerizable monomer having a long-chain alkyl radical such as long-chain alpha-olefins, long chain alkyl esters of alpha, beta-unsaturated acid, such as esters of acrylic and methacrylic acids, esters of lower unsaturated alcohols, such as vinyl and allyl alcohol esters of long chain fatty acids and long chain N-alkyl unsaturated fatty acid amides such as N-alkyl acrylamides.

The sulfenyl halides useful in the preparation of the novel polymers of this invention include aryl sulfenyl halides, such as benzene sulfenyl chloride, bromide, iodide or fluoride, e.g., benzene sulfenyl chloride, p-toluene sulfenyl chloride, butyl benzene sulfenyl chloride, etc.; halogen-substituted benzene sulfenyl halides, e.g., chlorobenzene sulfenyl chloride, 2,3-, 3,4-, or 2,4-dibromobenzene sulfenyl chloride, 2,4,6-trichlorobenzenesulfenyl chloride, pentachlorobenzene sulfenyl chloride, 2-chloro- 3-bromobenzenesulfenyl chloride, p-fluorobenzenesulfenyl chloride, etc.; and nitro-substituted benzenesulfenyl halides such as p-nitrobenzene sulfenyl chloride or 2,4-dinitrobenzenesulfenyl chloride or bromide, etc. There may also be used benzene sulfenyl halides such as 4 -chloro-2- nitrobenzene sulfenyl chloride, 2-chloro-4-nitrobenzenesulfenyl chloride, or 2-chloro-5-methylbenzenesulfenyl chloride,'i.e., benzenesulfenyl halides having a diversity of substituents in the benzene ring. Especially preferred in the present process are the chloroand/ or nitro-substituted benzene sulfenyl halides.

Suitable polyene hydrocarbons for forming the copolymers are 0 -0 dienes, for example, 1,3- and 1,4-

pentadiene, isoprene, 1,3-hexadiene, 1,3,5-heptatriene, 1,3- cyclopentadiene, methylcyclopentadiene, 1,3- and 1,4- cyclohexadiene, methylcyclohexadiene, and mixtures thereof. Other dienes are obtained by dehydration of unsaturated fatty alcohols such as lauroleyl, myri'stoleyl, pal'mitole'yl, oleyl, gadoleyl, linoleyl, ricinoleyl alcohols.

diene of this type which is particularly suitable is obtained by dehydrating oleyl alcohol which results in a 50 50 mixture of monoenes and dienes of C to C2 carbon atoms having the following properties:

Iodine vsiue ns 183 Hydroxyl value 0.4. 7 Boiling range 1-1 Over 100 C. at 1 mm. Hg. Appearance Colorless pale yellow li= quid. Melting range 55 to 70 C. (approx). Flash point (Cleveland open W v V 1.29 centistokes at 210 F. Specific gravity 25/25 C. 0.7965.

This material will be identified as Compound A.

Representing oil-solubilizin-g monomer compounds which are used to form the copolymers with the polyene hydrocarbons include alpha-unsaturated long chain hydrocarbons, runsaturated esters, unsaturated amides, e.g., such as decene-l, dodecene-l, tridecene-l, tetradecene-l, hexadecene-l, heptadecened, octadecene-l, tritriacontene-l, tetratriacontene-l, heptacontene-l, 4-methyldecene-l, 4,4-dimethy l-decene-1, 5,5-dimethylhexene-1, 5,5,7,7-tetramethyldecene-1, 4,4,6,6-tetramethylheptene-l, etc., vinyl deeanoate, vinyl lauroate, vinyl tridecanoate, vinyl rnyristate, vinyl pentadecanoate, vinyl palmitate, vinyl margarate, vinyl stearate, vinyl nonadecanoate, vinyl arachidate, vinyl behenate, vinyl 4,5,6-trimethyldodecan0- ate, vinyl 6,8,9-triethyl tridecanoate, vinyl 12-hydroxystrearate, vinyl 9,10-dihydroxystearate, vinyl chlorostreate, vinyl cyanostreate, vinyl acetylstreate, Vinyl dodecyl ether, vinyl tridecyl ether, vinyl tetracosyl ether, vinyl hexacosyl ether, allyl stearate, allyl dodecyl ether, N-lauryl methacrylamide, N-stearyl 'methacrylamide, N,N- distearyl methaorylamide, lauryl methacrylate, stearyl methacrylate and mixtures thereof.

The rnol ratio of the polyene hydrocarbon to the oil-solubilizing monomer compound can be varied within relatively wide limits, e.g., from U 10 to 10/1, preferably from 1/5 to 5/1, respectively. The polymer (prior to treatment with an aryl sulfenyl halide compound) should have a substantial amount of unsaturation.

About 0.66 mole of l-octadecene, 1.33 mole of 1- dodecene and 0.5 mole of Compound A in cyclohexane were reaction in the presence of a Ziegler catalyst at room temperature for about 24 hours. The catalyst was destroyed by addition of methanol and polymer thereafter purified by benzene washing and precipitating from alcohol and vacuum drying. The polymer had an average molecular weight of 300,000 and an average of 750 double bonds per polymer molecule as shown by promine number.

Example II About 0.5 mole of Compound A, 0.17 mole of 1- tetradecene and 0.34 mole of l-dodecene in benzene were reacted in the presence of the Ziegler catalyst as in Example I and under the conditions of Example I. The polymer formed had a molecular weight between 35 0,000- 400,000 and a bromine number of 50.

Examine III About 2 moles of pentadiene and 1 more of lauryl methacrylate and 1% ditertbutyl peroxide were reacted at 100 C. for about 24 hours. The polymer was purified by alcohol washing, filtered and dried. The resulting copolymer had a molecular weight of 3000-6000 and substantial unsaturation as shown by a bromine number of to 100.

Following essentially the procedures of Examples I-III, other polymers were prepared in accordance with the following tabulation:

Example Catalyst Temperature Polyene/oil-soluble monoolefins ratio IV Ziegler cat. as in Example I. Room temp Butadiene(2)/octadecene-1 (1).

V d0 (SO-70 C Isoprene(2) /octadecene-1 (1) VI Benzoyl peroxide. 80 C Isoprene(3)/lauryl methacrylatefl).

VII do C- Butadiene(2)/C14-C|s diene of dehydrated O14- O16 unsaturated fatty alcoh0l(1)/vinyl stearatefl).

VIII Ditert-butyl peroxide 80 C Pentadiene(3)lN-lauryl-methaerylamide(1).

IX do O Diene of ricinoleyl alcohol(3)llauryl methacrylate(1) stearylmethacrylate(1).

X--- do 100 C Diene of linoleyl alcohol(3)/al1yl stearatefl).

Depending on the monomers used, the polymers can be prepared thermally or in the presence of a suitable catalyst. Thus, with monomers such as butadiene, isoprene, Compound A'and long chain alpha-olefins such as alpha-dodecene or alpha-octadecene, the so-called Ziegler catalysts are preferred, such as combinations of aluminum trialkyls and a variable valence metal compound, e.g., titanium tetrachloride. In the formation of other types of oil-soluble polymers such as copolymers of the polyene' (e.g., butadiene, isopr-ene, or Compound A) with lauryl methacrylate or with vinyl stearate or with N-lauryl methacrylarnide, oxygen-yielding catalysts are preferred such as, for example, various organic peroxides,

The final oil-soluble polymeric additive is prepared by reacting the unsaturated copolymer, such as those of Examples I-X, with one or more of the sulfenyl halide compounds by any suitable means, such as described in Jour. Am. Chem. Soc., 75, 6030 (1953) or 78, 1201 (1958). Specifically, in carrying out the final reaction the sulfenyl halide is simply contacted with the unsaturated polymer at ordinary, increased or decreased temperatures, until formation of the halo-sulfur containing product has occurred. Depending upon the individual reactants employed, as well as on the quantities used, heating or cooling of the reactant mixtures may be required. In many cases, formation of the products takes place spontaneously, although the reaction may, if desired, be expedited by heating the reaction temperature and in dissipating the heat of reaction. Useful inert solvents and diluents are, e.g., benzene, toluene, hexane, ether, etc. An excess of either reactant and gradual introduc- 5 tion of the other may also result in smoother operation. The present reaction may also be effected at increased or decreased pressure, or in the presence of a catalyst; however, the ease of reaction at ordinary atmospheric pressure and in the absence of catalysts generally requires no control of the reaction by pressure variation or acceleration thereof by catalytic means.

The invention is further illustrated, but not limited by the following examples:

Example A Ina suitable vessel 40 grams of the oopolymer of Example II was dissolved in 200 ml. of benzene under a nitrogen atmosphere with stirring. To the mixture was added 30 grams of 2,4-dinitrobenzene sulfenyl chloride and the mixture was stirred at room temperature for about 72 hours. The chlorine-sulfurcontaining polymer was then precipitated from solution with methanol and then dissolved in benzene, filtered, precipitated with methanol and the procedure repeated. The polymer was then vacuum oven dried at 0.1 mm. 120 C. to give a polymer product having a plurality of beta-chloroalkyl 2,4-dinitrophenyl sulfide units having the following analysis:

Percent wt. Carbon 74.9 Hydrogen 11.6 Nitrogen 2.35 Chlorine 3.01 Sulfur 2.71

Example B The procedure of Example A was followed using the polymer of Example 11 and benzene sulfenyl chloride as the sulfenyl halide compound. The final polymer molecule contained over 500 units of groups distributed in the molecule.

Example C The procedure of Example A was followed using the polymer of Example I and 2,4-dinitro'benzene sulfenyl groups distributed in the molecule.

Following essentially the above procedures other polymers containing a plurality of halogen-sulfur-containing groups in the molecule were prepared in accordance with the following tabulation.

The halo-sulfur-containing polymers are oil-soluble and are used in amounts of from about 0.5% to about 20%, preferably from about 1% to about 5% by weight. However, under certain storage and use conditions, it is desirable to incorporate into oil compositions containing these polymers a small amount (0.1-10%) of an oilsoluble branched-chain aliphatic monohydric alcohol. These alcohols can eifectively stabilize such compositions without destroying the extreme pressure properties of such oil compositions.

The lubricating oil base is suitably selected from various synthetic oils or natural hydrocarbon oi-ls having a viscosity range of from 50 SUS at 100 F. to 250 SUS at 210 F. (SAE viscosity number ranging from SAE 5W to SAE The natural hydrocarbon oils are obtainable from parafiinic, naphthenic, asphaltic or mixed base cru'des, and/or mixtures thereof. Useful synthetic oils include polymerized olefins, alkylated aromatics, isomerized 'Waxes, copolymers of alkylene glycols and alkylene oxide (Ucon fluid, US. 2,425,755, 2,425,845 and 2,774,- 733) organic polyesters such as esters of an aliphatic dibasic acid and a monohydric alcohol, such as di-2-ethyl hexyl se'bacate or di-Z-ethyl hexyl adipate esters of polyhydric alcohols and monocarboxylic acids, such as pentaerythritol tetracaproate, and the like. Useful Ucon fluids are Ucon 50HB170, Ucon 50HB660 or Ucon LBSSOX, which are copolymers of ethylene and 1,2- propylene oxides; the diols as well as their monoand dial'kyl ethers are useful. I The hydrocarbon oil-s may be blended with fixed oils such as castor, lard oil and the like and/or synthetic oils as mentioned or silicone polymers and the like. Typical oils of this type are petroleum motor oils (a) and (b), characterized below, (A) being 7 parafiinic in character and (B) naphthenic in character:

Other suitable oils are specification gas turbine lube oils having the following properties:

Grade 1010 1065 Flash, COO, F 300 465 Pour, F 10 Viscosity, SUS at 100 F 69. 4 530 Neutral Number 0. 02 0:01 A sh None None The following compositions are illustrative of the invention, the percentages being 'by weight:

Composition A: Percent Example A additive 2 1010 mineral oil Balance Composition B:

Example B additive 2 1010 mineral oil Balance Composition C:

SAE 90 mineral oil Balance Composition I:

Example A additive Ucon 50HB660 (polyethylene-propylene glycol having a SUS viscosity at 100 F. of 660) Balance Composition J Example A additive 5 Di-Z-ethylhexyl sebacate Balance Compositions of this invention and other compositions were evaluated for their ability to impart to mineral oil (1) detergency as determined by the Carbon Black Dispersency Test described in the Journal of Colloid Science, vol. 12, October 1957, No. 5, pages 500522; at 100 C. and 5 r.p.m.; and (2) extreme pressure properties as determined in the Spur Gear Machine. The results are shown in Table I.

The Spur Gear Machine consists essentially of two geometrically similar pairs of gears connected by two parallel shafts. The gears pairs are placed in separate gearboxes, which also contain the supporting ball bearings. One of the shafts consists of two sections connected by a coupling. Loading is accomplished 'by locking one side The polymers of this invention are useful also for providing superior load-carrying properties in 1ubricating oils which contain minor amounts of other agents which are non-reactive with the polymer, such as silicone anti-foaming agents, alkylphenol anti-oxidants, polyacrylate estcr viscosity-index improvers, and the like.

- This application is a continuation-in-part of copending application Ser. No. 817,462, filed June- 2, 1959, now US. Pat. 3,105,818. v-

. The oil-soluble unsaturated copolymers used in making the new products of the invention have molecular weights ranging from about 2,000 to about 1,000,000 andpreferably from 3,000 to 500,000 as determined by the light scattering technique. The polymers also preferably have bromine numbers varying from 30 to about 200, and preferably 40 to 120.

I claim as my invention: p

1; As a new product useful as a lubricating oil additive a'mineral oil-soluble high molecular weight polymer containing a plurality of C C alkyl groups and groups attached to different carbons of a linear hydrocarbon chain where Q is an aryl, X is a polar group selected from the group consisting of halogen, amino, nitro and sulfo groups, and x and y are integers of at least 1, and z is a number from 0 to 2, the molecular weight of the polymer ranging from 10,000 to 500,000 as determined by the light scattering technique.

2. The product of claim 1 wherein the halogen is chlorine, Q is a benzene ring and X is selected from the group consisting of chlorine, nitrol and mixtures thereof when z is 2.

3. As a new product useful as a lubricating oil additive, a mineral oil-soluble linear hydrocarbon polymer containing C -C alkyl groups and Cl,

groups randomly distributedalong a linear hydrocarbon chain with the latter two groups being attached to adjacent carbon atoms of an alkyl side chain and X is selected from the group consisting of chlorine and nitro group and mixtures thereof, the molecular weight of the polymer ranging from 10,000 to 500,000 as determined by the light scattering technique.

4. As a new product useful as a lubricating oil additive, a mineral oil-soluble linear hydrocarbon polymer containing a plurality of side chains randomly distributed along a linear chain, the side chains being (1) C r-C alkyl groups, and (2) alkyl groups substituted on adja-' cent carbon atoms of the alkylgroups with a chlorine atom anda (N ah group, the number of side chains being at least 10, and

the molecular Weight of the polymer being at least 1,000.

5. A new product useful as a lubricating oil, a mineral oil-soluble linear hydrocarbon polymer containing a plurality of side chains randomly distributed along a linear chain, the side chains being (1) C -C alkyl groups, and (2) alkyl groups substituted on adjacent carbon atoms of the alkyl groups with a chlorine atom and a 9 r 10 group, the number of such side chains ranging from 100 OTHER REFERENCES to 300, d the molecular Weight of the Polymer being at Kharasch et al.: 71 JACS 2724, Characterization of least ,000. Olefins With Dinitrobenzene Sulfenyl Chloride, 1949.

References Cited y the Examiner 6 JOSEPH L. SCHOFER, Primary Examiner.

UNITED STATES PATENTS LEON I. BERCOVITZ, Examiner. 2,952,291 9/1960 Serniuk et a1. 26079.5 DENSONM HENDERICKSON,

3,041,283 6/1962 Calhoun et a1. 260-795 Assistant Examiners, 

1. AS A NEW PRODUCT USEFUL AS A LUBRICATING OIL ADDITIVE A MINERAL OIL-SOLUBLE HIGH MOLECULAR WEIGHT POLYMER CONTAINING A PLURALITY OF C8-C20 ALKYL GROUPS AND 